linux-kernel - Re: [PATCH 2/5] iio: adc: xilinx: use devm_krealloc() instead of kfree() + kcalloc()

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Date:   Tue, 27 Oct 2020 13:18:36 +0200
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     Bartosz Golaszewski <bgolaszewski@...libre.com>
Cc:     Bartosz Golaszewski <brgl@...ev.pl>,
        Jonathan Cameron <jic23@...nel.org>,
        Lars-Peter Clausen <lars@...afoo.de>,
        Peter Meerwald-Stadler <pmeerw@...erw.net>,
        Michal Simek <michal.simek@...inx.com>,
        linux-iio <linux-iio@...r.kernel.org>,
        linux-arm Mailing List <linux-arm-kernel@...ts.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 2/5] iio: adc: xilinx: use devm_krealloc() instead of
 kfree() + kcalloc()

On Tue, Oct 27, 2020 at 12:40 PM Bartosz Golaszewski
<bgolaszewski@...libre.com> wrote:
> On Tue, Oct 27, 2020 at 11:29 AM Andy Shevchenko
> <andy.shevchenko@...il.com> wrote:
> > On Tue, Oct 27, 2020 at 12:04 PM Bartosz Golaszewski <brgl@...ev.pl> wrote:
> > > On Tue, Oct 27, 2020 at 10:33 AM Andy Shevchenko
> > > <andy.shevchenko@...il.com> wrote:

...

> > I meant devm_krealloc(). It should work in this case without your
> > additional "fix" patch.

> I know, this is why I sent the fix separately. The fix is still
> correct on its own.

My point is it's not needed. At all.
It will actually make a regression. But this is for discussion in that thread.

...

> > > Or maybe add devm_krealloc_array() which would perform the checks
> > > behind the scenes?
> >
> > Maybe. But what to do in the cases when you have struct with flexible
> > arrays, like
> > struct foo {
> > ...
> >  type bar[];
> > };
> >
> > ?
>
> Just use regular devm_krealloc() with struct_size()?
>
> >
> > And you do kzalloc(sizeof(foo)) followed by krealloc(). The above name
> > (krealloc_array) may be a bit ambiguous.
>
> But devm_krealloc_array() would only be useful for memory allocated by
> kmalloc_array() or kcalloc(). I don't see what's your point.

Naming ambiguity.
Here I'm not against it. If you think it's a good idea, go for it!

-- 
With Best Regards,
Andy Shevchenko